Headphones are widely used to closely couple the sounds they produce, such as music, etc., to the listener's ear such that the sounds are relatively free from interference from other sounds present in the listener's environment. Headphones can be classified into open-type headphones and closed-type headphones in accordance with the classification methods.
Open-type headphones can minimize dull sounds because they are configured in such a way that sounds from a diaphragm of a speaker are not confined but are able to spread. On the contrary, closed-type headphones generate dull sounds.
The closed-type headphones are tightly fitted into the ear canal to minimize noise from the outside. Therefore, the closed-type headphones are free from interference from the outside noise, so the listener can listen to audio sounds from the diaphragm of the speaker, such as music, in a noisy environment. Also, audio sounds from the diaphragm of the speaker do not escape the listener's environment to be overheard by, or interfere with, the environment of bystanders.
However, when the listener wears the closed-type headphones for a relatively long period of time, the pads contacting the ears make the listener feel uncomfortable in comparison with the open-type headphones. Furthermore, since the air pressure of audio sounds from the diaphragm directly impacts the eardrum, the eardrum can be injured.
Meanwhile, to utilize the advantages of both the open-type headphones and the closed-type headphones, headphones have been proposed which are configured in such a way that a waveguider is mounted on the open-type headphones, respectively. The headphones having a waveguider will be described in the preferred embodiments of the present invention.
The conventional headphones form air inlets into which air instantly flows as the diaphragm of the speaker is vibrated. The technique that controls the amount of air flowing into the air inlets of the headphones was disclosed in Korean Patent Nos. 0767390 and 0767391, which are related to the headphones having an equalizer.
The conventional headphones having an equalizer close or open air outlets formed on the back side of their respective housings to boost bass and treble. However, since the closing process or the opening process of the air outlets is performed within the headphones, a listener cannot monitor by how much the air outlets are closed or opened and thus the fidelity of the headphones is reduced.